Changing sign



Nov. 7, 1933. H. M. RUSSELL CHANGING .SIGN

Filed May 3, 1932 2 Sheets-Sheet l INVENTOR.

NOV. 7, 1933. H. Mv RUSSELL 1,933,763

CHANGING SIGN Filed May 3, 1932 2 Sheets-Sheet 2 INVEN TOR.

Patented Nov. 7, 1933 CHANGING SIGN Henry M. Russell,

Application May 3, 19

10 Claims.

The purpose of my invention is to provide a sign which will show certain letters or a certain picture when a certain part of the substance of which the sign is composed is immersed in liquid; and will show other and different letters, or another and different picture when the said part of the said substance ceases to be immersed in liquid, and vice-versa.

The word signf. as used in this specification is intended to mean either a picture or lettering, or a combination of a picture and lettering; or any other symbols or marks, and the substance upon which such symbols or marks are placed.

The invention is based upon the principle that the reflection of light from the inner surface of a transparent substance ceases when a transparent, or partially transparent, liquid comes into contact with such surface.

Referring now to the drawings in which any given numeral appearing more than once always refers to the same thing:

Fig. 1 shows an ordinary drinking glass to which my invention has been applied.

Fig. 2 shows a cross-section of the same glass.

Fig. 2A shows a portion of the same crosssection shown in Fig. 2, enlarged and having the lettering and background coloring exaggerated in thickness, so as to make them visible in cross-section.

Fig. 2B shows a view of the same portion of the glass shown in Fig. 2A as that portion would look if viewed from the inside of the glass.

Fig. 3 shows a cross-section of a vessel having the improved sign on one side, the sign being made up of a number of prisms instead of a single prism.

Fig. 4 shows an isometric view of the same vessel and sign shown in section in Fig. 3.

Fig. 5 shows a form of a sign embodying my invention and intended for use in cases in which the whole sign will at times be completely immersed in liquid, as shown in this figure.

' Fig. 6 shows the same sign not immersed in liquid.

The numeral 7 indicates the sign in the form of a raised prism. This prism is preferably a part of the glass itself. But it may be made of 50 a separate piece of glass or other transparent material and cemented to the drinking glass with suitable transparent cement.

8 indicates the lettering which is seen by one looking thru the upper face of the prism when 55 the glass is full of liquid.

Wheeling, W. Va.

32. Serial No. 608,920

9 refers to the lettering which is seen by one looking thru the upper face of the prism when the glass is empty. As shown in the drawings, the design 9 is visible to one looking at the bottom face of the prism. It is shown this way merely to make the explanation more easily understood. In practice it is preferable to have the design 9 covered up so that it cannot be seen at all from the outside of the glass, except when it becomes visible thru the upper surface of the prism.

Fig. 2 shows a cross-section of the same glass, the section being made on a plane passing thru the center of the glass and at right angles to the upper and lower faces of the prism.

Fig. 2A shows an enlarged cross section of the prism and a portion of the side of the glass shown in Fig. 2.

Fig. 2B shows an inside view of the same portion of the glass and the prism which is visible through it. The lettering and the background coloring are exaggerated in thickness in Fig. 2 A so as to make them clearly visible. In Figs. 2-A and 2B as in Figure 2, numeral 8 refers to the letters inside of the glass; numeral 9 refers to the lettering on the lower face of the prism; 7' refers to the coloring on the front of the prism and 10 refers to the position of the observer.

Numerals 17 and 18 show the line at which the plane of the section illustrated in Fig. 2A intersects the portion of the glass shown in 2B. In Fig. 2-A the portions of the letter and of the background cut by the said plane are shown in black. The letters on the inside of the glass as shown in this Figure 2-A indicated by the numeral 8 are not made of reflecting material but are colored. And they disappear because of lack of contrast between the color of the letters and the color of the background on the lower face of the prism.

The inside surface of the glass is preferably flat just behind the prism and parallel with the outer surface of the prism. But this is not absolutely necessary.

In the form of the invention shown in Figs. 1 and 2, the lettering 8, in this case being the letters Y-e-s, is formed of opaque silver, or other opaque reflecting material, applied to the inner surface of the glass, in the same way that silver, or other opaque reflecting material is applied to a mirror. The background around the letters is clearglass.

The lettering 9 in this case being the letters No, is formed of dark coloring matter applied to the glass. The background around the letters N-o (9) is clear glass with small dots upon it.

As stated above this particular arrangement is shown because it makes the explanation more clear, though it is preferable to have the space around the letters N-o covered with opaque coloring matter of a different color or a different tone from that of the letters.

The numeral 10 indicates the position of the observer. Assume now that the glass is empty. Since the observers line of vision is approximately perpendicular to the upper surface of the prism, there is practically no refraction, and his line of vision makes an angle of slightly less than forty-five degrees with the inner surface of the glass. There is, therefore, total reflection from such inner surface, and the uncovered surface of the glass is a perfect mirror.

The letters Y-es, being applied silver, are also perfect mirrors. So, the whole surface is an unbroken mirror. In this mirror the observer sees a reflection of the word No. And he does not see the form of the letters Yes, nor does he see anything to indicate that any such letters are there.

Now assume that the glass has been filled with water or other transparent, or partially transparent liquid, up to the level indicated by the dotted line (11). The presence of the water in contact with the inside surface of the glass kills the total reflection which formerly took place. And the observer now looks thru the inside surface of the glass (where such surface is not covered by the letters Y-e-s) in the direc- "tion indicated by the numeral 12, and sees the or of half-tone dots.

side of the glass which may, if desired, be white; or sees the reflection of the bottom of the glass, which may be white, or the table cloth, if the side and bottom are left transparent. In any tions of the letters N-o can be seen on the Y and e of the word Yes. If it is desired to have the letters N-o disappear more completely, this may be accomplished by having either or both sets of letters made of thin lines,

above illustrate one form of my invention. But

I do not wish to limit my invention to signs with the letters located as above shown; nor to signs with silver letters or pictures, nor to signs with letters or pictures of any particular tones or colors.

The broad idea upon which the invention is based is the idea that bringing transparent or partially transparent liquid into contact with .the surface of another transparent material destroys the reflection from such internal surface and permits the observer to see instead, whatever is back of that surface.

My invention includes the placing of two different sets of letters or pictures in two different places, and formed of two different materials or colors, so that one set will be more plainly visible from a given point when such internal reflection is taking place, and the other set will be more plainly visible when such internal reflection is not taking place.

The letters located at 8 may be colored instead of silver and may be made to disappear by having the background around the letters at 9 the same color as the letters at 8.

Figs. 3 and 4 show respectively a cross-section of and an isometric view of a design of the improved sign made up of a number of different prisms, instead of a single prism, as in Figs. 1 and 2. The action so far as each individual prism is concerned is precisely the same as that shown in Figs. 1 and 2. But the lines or design seen respectively thru the different prisms are so arranged that together they form one single design when the vessel is full; and a different single design when the vessel is empty.

In the case shown in Figs. 3 and 4, one of the designs is a lozenge, and the other is a rectangle. The vessel is partly filled with liquid, so the observer sees part of the lozenge on that part of the sign which is above the level of the liquid; and sees part of the rectangle on that part of the sign which is below the level of the surface of the liquid.

The line 12, 13 indicates the line of vision of the observer, thru one prism. His lines or vision thru the other prisms would be nearly parallel thereto.

Figs. 5 and 6 show a form of sign embodying my invention and intended for use in cases in which the whole sign will at times be immersed in liquid, and at other times will not be immersed. Both views are side views, not in cross-section.

14 shows the point of View of the observer. In this case the sign is in the form of a prism,

two sides of which are at right angles, and'a third at an angle of forty-five degrees. One set of letters or one picture is' placed at 15, and the other set of letters or the other picture is at 16. When the sign is completely immersed in transparent liquid, as in Fig. 5, the observer sees the letters or picture 15; and when the sign is not immersed, as in Fig. 6, the observer sees the letters or picture 16.

The word design as used in the following claims is intended to include numerals, punctuation marks, and other symbols and pictures,

images, or any other portrayals of objects or things or a combination of any of the foregoing.

Having thus described my invention, I claim:

1. A changing sign consisting of a prism of transparent material having two different designs located on two of its respective surfaces; the said designs being so located and formed of such materials that one of the said designs shall be visible from a given point of view when one face of the said prism is in contact with a liquid; and the other of said designs shall be visible and the first of the said designs shall be invisible when the said face is not in contact with liquid.

2. A changing sign consisting of a prism of transparent material having two different designs located on two of its respective surfaces,

the said designs being so located and formed of such colors, that one of the said designs shall be visible from a given point of view when one face of the said prism is in contact with a liquid, and the other of the said designs shall be visible; and the first of the said designs shall be invisible when the said face is not in contact with liquid, and a suitable container attached to such sign for holding the said liquid in contact with the said surface.

3. A changing sign consisting of a prism of transparent material forming part of a drinking glass or other suitable vessel; the upper surface of the said prism slanting away from the side of the said glass, and the lower surface of the said prism slanting toward the said glass; one design on the inner surface of said glass, approximately opposite the mid-portion of the said prism, and a different design on the lower face of said prism.

4. A changing sign consisting of a prism of transparent material attached to a drinking glass or other suitable vessel; the upper surface of the said prism slanting away from the side of the said glass; and the lower surface of the said prism slanting toward the said glass; one design on the inner surface of said glass, approximately opposite the mid-portion of the said prism, and a different design on the lower face of said prism; the first mentioned of said designs being some opaque reflecting medium.

5. A changing sign consisting of aprism of transparent material forming part of a drinking glass or other suitable vessel; the upper surface of the said prism slanting away from the side of'the said glass, and the lower surface of the said prism slanting toward the said glass; one design on the inner surface of said glass, approximately opposite the mid-portion of the said prism, and a different design on the lower face of said prism; the first mentioned of said designs being some opaque reflecting medium; and the other of said designs being in one color or tone upon a background of different color or tone.

6. In a changing sign the combination of a prism of transparent material, a design in a certain color or tone on one face of said prism, a background of the same color or tone on another face of said prism and located respectively that when no face of the said prism is in contact with liquid, the said background will appear around the said design, thereby rendering the said design wholly or partly invisible,. and when a certain face of the said prism is in contact with liquid, the said background shall not be visible and the said lettering shall appear in contrast with another background.

7. In a changing sign the combination of a prism of transparent material, a design in a certain color or tone on one face of said prism, a background of the same color or tone on another face of said prism and located respectively that when no face of the said prism is in contact with liquid, the said background will appear around the said design, thereby rendering the said design wholly or partly invisible, and when a certain face of the said prism is in contact with liquid, the said background shall not be visible and the said lettering shall appear in contrast with another background; and a suitable container for holding liquid in contact with the said face of the said prism.

8. A changing sign consisting of a prism attached to the transparent side of a container for a liquid, one design on the inner surface of said transparent side of said container, and another design upon one of the outer faces of said prism.

9. In the changing sign, a combination of a vessel for holding liquid and having one side or a portion of one side transparent and attached to and forming part of the said transparent side or portion, a plurality of transparent prisms, each of said prisms having on it certain markings which are visible thru the upper outside face of such prism when the inside face of such prism is in contact with liquid; and certain other markings which are visible thru the said upper outside face when the said inner surface is not in contact with liquid. 110

10. In the changing sign a combination of a vessel for holding liquid and having one side or a portion of one side transparent and attached to and forming part of the said transparent side, or portion, a plurality of transparent 115 prisms, each of said prisms having on it certain markings which are visible thru the upper outside face of such prism, when the inside face of such prism is in contact with liquid; and certain other markings which are visible thru the said upper outside face when the said inner surface is not in contact with liquid; the said markings being so placed with relation to each other that the markings on all said prisms shall form one design when the inner surface of the side to 125 which said prisms are attached, is in contact with liquid; and shall form another and different design when none of such surface is in contact with liquid. 

